Hydro v5.0 subsurface water budget leak
Posted: Thu May 05, 2016 12:13 pm
Stepping through subsurface model processes we notice infiltrated water and water held in soil stores at the last timestep of a project simulation do not equal losses from soil (ET) and baseflow. This is mainly an issue with certain extreme parameter sets derived from auto-calibration.
In most cases (parameter sets) this leak affects the model by less than 5% of incoming precipitation, and generally the model results make sense. This leak does not appear to be significant for the majority of parameter sets, including the Suggested Default Parameters. We greatly see the effect of this leak when calibration creates certain parameter sets (such as 'super soil' parameter sets that can infiltrate extreme amounts of water and too rapidly create too much baseflow, i.e. base flow making up >95% of total flow), and we are not sure of the full extent of the population or parameter ranges that trigger problematic imbalances.
We are actively tracking down which parameter sets trigger problematic imbalances and where bugs exist in the code for subsurface processes, in order to resolve this issue. This will be addressed in a future update to Hydro v5 and will be corrected in the upcoming Hydro v6.
In most cases (parameter sets) this leak affects the model by less than 5% of incoming precipitation, and generally the model results make sense. This leak does not appear to be significant for the majority of parameter sets, including the Suggested Default Parameters. We greatly see the effect of this leak when calibration creates certain parameter sets (such as 'super soil' parameter sets that can infiltrate extreme amounts of water and too rapidly create too much baseflow, i.e. base flow making up >95% of total flow), and we are not sure of the full extent of the population or parameter ranges that trigger problematic imbalances.
We are actively tracking down which parameter sets trigger problematic imbalances and where bugs exist in the code for subsurface processes, in order to resolve this issue. This will be addressed in a future update to Hydro v5 and will be corrected in the upcoming Hydro v6.